1. Field of the Invention
This invention relates to the art of making tubular sleeves or bands suitable for application to the neck or neck and closure portion of filled bottles to comprise neck labels, and more particularly to novel method and apparatus for forming such labels from heat-shrinkable relatively-stiff cellular sheet thermoplastic material of appreciable wall thickness to permit their uniform flat folding.
2. Description of the Prior Art
In one method of providing endless bands for necks of bottles, such as salad oil bottles and the like, the banding material has frequently been comprised of thermoplastic material such as polyvinyl or polyethylene, or a cellulose derivative having a high coefficient of shrinkage. In a considerable portion of the manufacture of such banding material, the bands are comprised of films or film-like material which is formed by extrusion as a seamless tube of substantially-circular transverse section. The film tube normally has longitudinal fold-defining lines at opposite sides of its diameter. After the extruded material of the tube is fully hardened, the tube is folded at the fold lines to form a two-ply extremely flexible flat ribbon. The tube ribbon is then taken for use in a banding machine which severs precise axial lengths of such tubing for application to individual bottles. The band is slipped over the neck of the bottle, the band being shrunken in response to physical conditions appropriate to the selected banding material. The band then tightly grips the bottle neck. In some cases, the bottles must be preheated to facilitate uniform application of the bands.
To open the folded ribbon-like strip of tubular material has usually required a pair of juxtaposed suction heads arranged to engage opposite sides of the ribbon at points substantially midway between the fold lines and then separating the suction heads. In the case of film-like materials which are extremely thin and flexible, this operation has often encountered difficulty in that the film tube has stuck to one of the heads and remained unopened, thus failing to mount an individual neck band on a given bottle. Also an adhesive must frequently be employed to attach the heat-contracting flexible material to the bottle neck.
When the neck labels are formed on the banding machine, such as by severing individual lengths of the tubular label stock from rolls, the roll stock must be very precisely severed to align the preprinted or decorated information on each label which patterns can and do vary in length. Also when the number of several labels on a given roll does not equate to the number of bottles to be labeled, small rolls of label stock can and do remain unused and are frequently wasted.
The invention disclosed and claimed in U.S. Pat. No. 4,013,496 to S. W. Amberg, issued Mar. 22, 1977, entitled, "Method For Producing Shrunken Pilfer-Proof Neck Labels On Containers" relates to a production machine and process for producing labelled bottles. This invention pertains to a practical method for applying a hollow tubular sleeve or band of shrinkable cellular polymeric material over the neck and closure skirt portions of a bottle and controlling the wrinkles of the sleeve or band upon heat-shrinkage, resulting in a superior labelled package from the standpoint of appearance and performance. Also, that invention provides a machine capable of automatic production for making the sleeves of shrinkable material from a predecorated or preprinted web supply and assemblying the sleeves onto the upper ends of the capped bottles processed by the machine. The machine provides a sub-assembly structure to move the web past a device for forming cross-flutes or pleats in the material at spaced intervals to minimize wrinkling on heat-shrinkage. That machine forms the sleeves or bands on the machine just prior to their application to the selected containers. The referenced patent does not relate to the pre-manufacture of flat-folded distinctive bands or labels adapted to use on a wide variety of banding or labeling machines for their subsequent application to containers which are not preheated and without the use of bonding adhesives. Also, the plural pleats are formed in the roll stock just prior to wrapping the cut blank on the forming mandrel where its ends are joined; thus, minor differences in the sidewall lengths after end seaming occasionally prevent flat-folding of the bands.